<p>Those numbers sound reasonable. There’s a convergence towards a 3.5 GPA as students progress during their time at Caltech. For people who racked up A+'s in core, the A+'s become harder to obtain later (ie, they’re very rare in the upper level courses) while people who struggled in core can start to choose courses they are stronger at. Especially by senior year, most people should have plenty of flexibility to choose courses they want to (and are better at or have more liberty to pass/fail their hard electives).</p>
<p>For people in the harder majors, junior year is more difficult than sophomore year but I don’t know of any major where senior year is harder than even sophomore year.</p>